NGC 1360:知更鸟蛋星云



NGC 1360: The Robin’s Egg Nebula
Image Credit & Copyright:
Dong Liang

Explanation: This pretty nebula lies some 1,500 light-years away, its shape and color in this telescopic view reminiscent of a robin’s egg. The cosmic cloud spans about 3 light-years, nestled securely within the boundaries of the southern constellation Fornax. Recognized as a planetary nebula, egg-shaped NGC 1360 doesn’t represent a beginning though. Instead it corresponds to a brief and final phase in the evolution of an aging star. In fact, visible at the center of the nebula, the central star of NGC 1360 is known to be a binary star system likely consisting of two evolved white dwarf stars, less massive but much hotter than the Sun. Their intense and otherwise invisible ultraviolet radiation has stripped away electrons from the atoms in their mutually surrounding gaseous shroud. The predominant blue-green hue of NGC 1360 seen here is the strong emission produced as electrons recombine with doubly ionized oxygen atoms.

Tomorrow’s picture: supernova remnant

NGC 1360:知更鸟蛋星云
Dong Liang

说明: 在这幅望远镜影像里,位于1,500光年远处的这团美丽星云,形状和色泽酷似知更鸟蛋。它位在南天的天炉座之内,跨幅在3光年左右。它的分类是行星状星云,因此蛋形的NGC 1360并不是恒星生命的起点,而是一颗年老恒星演化的短暂最后阶段。在这张影像的中心所见到的NGC 1360中心星,其实极可能是由2颗高度演化白矮星所组成的双星系统,二者的质量皆小于太阳,但远比太阳炽热。它们强烈但不可见的紫外辐射,不停把包覆它们的周遭气体云里的原子之电子剥出去。NGC 1360鲜明的水蓝色泽,则是来自电子与双电离的氧原子复合时,所发出的明亮辐射。

明日的图片: supernova remnant